$6\; g$ of an unknown saturated and non-cyclic secondary monoalcohol are treated with an excess of sodium. We collect NTP $ 1.12 \; L $ of hydrogen. Find this alcohol ! First look for the number of moles of hydrogen !
For answers, use (possibly multiple times) the arrows ↑ and ↓ at the top! Complete please this question before moving on to the next!
$n_{H_2}$ $=$ $\frac{V}{22,4}$ $=$ $\frac{1.12}{22.4}$ $=$ $0.05\; mol$
Then the number of moles of alcohol !
$n_{alcool}$ $=$ $2\cdot 0.05$ $=$ $0.1 mol$
Then the molar mass of alcohol !
$M$ $=$ $\frac{m}{n}$ $=$ $\frac{6.0}{0.1}$ $=$ $60 \frac{g}{mol}$
What is the general formula of a saturated and non-cyclic monoalcohol?
$C_nH_{2n+2}O$ ou $C_nH_{2n+1}OH$
Find n (Indication: find the molar mass from the general formula)
$M$ $=$ $12n+2n+2+16$ $=$ $60$ Solving this equation: $n=3$
Give the molecular formula, condensed formula and the scientific name of this alcohol !
$C_3H_8O$ $CH_3-CHOH-CH_3$ Propan-2-ol
